Might I make a suggestion?
Those letters look itty bitty. And as good as your first cut is, it's going to be insanely difficult to get a clean finish from those things.
What
I would do personally is get a vynil negative of the text made up (anybody that does rear-window car decals can turn 'em out on the cheaps), and use it as a template (Use paper, or light-adhesive tape and an Xacto if the first isn't in your budget) for a few coats of white spray paint.
My very favorite faceplate artist SpaceGhost2K is a perfect example:



If done correctly, using a vynil negative some amazing results for very little work.
That's just a suggestion though. If you're ballsy enough to give it a shot, the best of luck to 'ya!